Medical devices are made with great care. Medical needles have traditionally been made on an individual basis and have, consequently, been relatively expensive to produce. Several patents disclose exemplary manufacturing processes.
U.S. Pat. No. 3,359,978 to R. M. Smith, Jr., discloses a process beginning with stamping a needle pattern from steel flat stock. A groove or trough is formed in the flat stock to provide a weakened region for needle separation when used for catheter implacement. The flat stock is then rolled to a circular needle configuration. Alternatively, Smith describes a process whereby flat sheet stock is first formed into a tube, and then grooves on opposite sides of the tube are milled along the exterior. Thereafter, wings or flaps are soldered, welded or braised to the tube for needle splitting purposes. In either case, the needle tip is sharpened after the tubular shape is formed.
U.S. Pat. No. 4,100,393 to Ronald B. Luther describes a process beginning with tube stock which is cut, beveled at one end, and flared at the other end. A laser is used to weld wings at the appropriate location to the tubular needle. The laser is also used to provide a score line on one side from one end of the needle to the other and a cut line on the other side. To complete the tip, the beveled surfaces are honed.
U.S. Pat. No. 4,377,165 to Ronald B. Luther shows a somewhat different process. This process comprises continuously forming a needle blank from flat sheet metal or from a roll. A groove of controlled depth is formed along the blank stock which thereafter is rolled to a hollow configuration and then cut into individual needle barrels with a longitudinal slit parallel to and on the opposite side of the barrel as the groove. The needle ends are formed and wings are welded on opposite sides of the groove.
U.S. Pat. No. 4,449,973 to Ronald B. Luther shows still another process for making a medical needle. In this patent, Luther forms a groove on flat stock and then rolls the flat stock into a barrel. The groove may even be partial slits. Thereafter, the barrel may be hardened by cold drawing it into a smaller diameter and laser welding it partially closed at any slit apparently to improve cannula strength. The needle tip is ground and the end opposite is formed for mounting into wing holders.
Thus, the known art discloses a number of different techniques for making medical needles. Each of the techniques, however, is directed to working with a single needle at a time. As a resut, the manufacturing process, regardless of type, is relatively expensive. The present invention is directed to a process and the produce of the process wherein a plurality of medical needles are formed through a series of steps which leave individual needles unitarily attached to a part of the steel stock as a carrier strip.